Venetian blind



B. WALKER VENETIAN BLIND Sept. 15, 1953 Filed Jan. 23, 1950 PatentedSept. 15, 1953 UNITED STATES PATENT OFFICE VENETIAN BLIND Brooks Walker,Piedmont, Calif.

Application January 23, 1950, Serial No. 139,981

1 Claim. 1

This invention pertains to improvements in Venetian blinds and,particularly, the Venetian blinds employing tapes made of plastic ormaterial that is too stiff to fold at each ladder station which isusually required when the lifting cords go between the side members ofthe ladder tape and the edge of the slats as is shown in my Patent No.2,200,349 which allows the slats to be removed without unlacing the liftcords. In this invention, it is proposed that the lift cords be placedoutside of the ladder tapes but adjoining the ladder tapes so as to tendto keep the ladder tapes in alignment with the lift cords. The slats arepreferably secured to the ladder tapes by tongues cut in the slats whichengage the cross rungs of the ladder tape or some similar satisfactorymethod.

Another object of this invention is to provide the ladder tape with anoffset portion in the stiff or semi-stiff cross member so as to properlyposition the slat relative to the cross member when the substantiallystiff cross member is engaged. by the tongue in the slat.

Another object of the invention is to provide means whereby the tape ina blind may be readily removed without unlacing the lift cords from theslats.

Further objects of the invention will be more clearly pointed out in theaccompanying specifications and claim.

I have illustrated my invention by way of example in the accompanyingfigures, in which:

Figure 1 illustrates a front view of a Venetian blind incorporating oneform of the invention.

Figure 2 is a plan view of the cord arrangement in the head rail of theconstruction shown in Figure 1.

Figure 3 is a sectional view taken above one of the slats in the blindshown in Figure 1.

Figure 4 is an enlarged view partly cut away showing in greater detailthe construction of the ladder tape, lift cords, cross rungs, and slatengagement.

Figure 5 is a, partial view partly cut away showing the construction ofthe lift cords, head rail, tilt rail and upper portion of the laddertape.

In all views, like numerals of reference refer to corresponding parts.

In Figures 1 through 5, I have shown a Venetian blind in which there isa head rail I0 and tilt rail 6. The tilt rail is supported on a pivotbracket I8 at the right hand end as shown in Figure 1 and is tilted bythe usual tilt mechanism 1 shown on the left hand side of Figure 1. Thetilt mechanism is tilted by tilt cords la and 1b in a conventionalmanner. slats may be of the curved metal type or of plastic, wood orother suitable material, and are supported in spaced relationship byladder tapes 8 and 9. These ladder tapes are preferably of the plastictype with thread inserts in the side member to prevent stretching andwith metal inserts in the cross members 9a which can be permanentlydeflected as shown in Figure 4 to properly mesh and nest with thetongues 5a and 5b of the slat 5 as shown in Fig ures 4 and 5. However,any other type of tape with a reasonably stiff cross member may be usedwith the offset in the cross member to properly position the slatrelative to the cross rungs and relative to the tape as well as makingthe problem of connecting the slat to the cross rung easier than if astiff cross member is used without the offset, in connection with slatshaving tongues.

With plastic type of tape, the side members are often somewhat stifferthan with a fabric type of tape and some resistance has been found tothe tape having to fold at every slat level when the cord passes betweenthe slats and the side members of the ladder tape as is shown in myissued Patent No. 2,200,349. In order to avoid this and to allow thetape side members to fold in the conventional manner with one fold awayfrom the slats and two slats in between and then a fold inside of theedges of the slat pile with one slat over and one slat under the foldbetween the slats, and then an outside fold around two slats in the slatpile so that the tape actually folds only once for each two slats ratherthan once for every slat as is the case when the cord runs between theedge of the slats and the side members of the ladder tape, preventingthe folding of the tape in between the slats in the slat pile, the cordis disposed externally of the slats and beyond the opposite edges of theside members of the ladder tape. In order to make the slats removableand not have the lifting cord go between the slats, I have provided alifting cord arrangement in which four lifting cords are used with twolifting cords at each ladder tape, lifting cords 34 and 3| being on theroom side of the slats and preferably on the outside relative to thecenter of the blind edge of the ladder tape, that is, as viewed inFigure 1, lift cord 34 is to the left of ladder tape 9 and lift cord 3|is to the right of ladder tape 8. Two other lift cords, 33 and 32, areat the back of the blind, 33 being to the right of ladder tape 9 and 32being to the left of ladder tape 8. By this location of the lift cordsas shown in Figures 1 and 3, it is seen that there is no interferencewith the folding of 3 the tape by the lift cords and that the slats canbe removed and that the lift cords, because of their location, will holdthe slat pile in alignment during lifting operations so that it cannotspill over to the right or the left at either ladder tape which would bethe case if only one lift cord were used at each ladder tape, such as 3|and 33 respectively. These lift cords on both sides of the ladder tapetend to keep the ladder tapes in line with the lift cords which tend tomaintain a vertical position due to the loading on them during thelifting operation. The lift cords preferably pass through cord lock l1and head rail 10, and then down through drilled and reamed holes ll, l2,l3, and M as shown in Figure 2. After passing through the center holesll, I2, I3, and I4, the cords then pass around the tilt rail 6 and downalong the edges of the slat at the edges of the ladder tapes 8 and 9respectively. Lift cords 3 I, 32, 33, and 34 are attached to the bottomrail 4 in a suitable manner as by a tack or by going into a drilled holewith an enlargement suitable for receiving the knot, or any othersuitable manner. The ladder tapes 8 and 9 are suitably looped over thetop of the tilt rail 6 and the bottom rail 9, and are either secured sothat the two side members of the ladder tapes are attached together bystapling, sewing, cementing, or other suitable manner, or they may betacked or stapled to the tilt rail and head rail. If they are merelylooped over and the two side members are attached together, then theladder tapes may be removed from the blind for cleaning or replacementwithout having to thread the lifting cords through all of the slats inorder to replace the ladder tapes-it merely being necessary to detachthe lift cord on the outside of the ladder tape where it is attached tothe bottom rail so that the ladder tapes may be removed. If the methodof attaching the bottom of the ladder tape sides together is adetachable form, such as by a snap, pins, clips, hooks, etc. so that thetwo sides of the bottom of the ladder tape may be separated, then itwill not be necessary to disconnect either of the lift cords at eitherladder tape in order to remove the ladder tapes for replacement,cleaning, or other purposes. The lift cords may be of the usual Venetianblind cord type, or two of the lift cords may be of this type and theother two (preferably the ones at the front 34 and 31) may be of wire,like piano wire, and joined with the other cord lifts at the equalizer35. Another construction that would be possible in case there wereobjection to the size of fabric lift cords would be the use of four wirelift cords joined together at the equalizer 3 and then a fabric corddropped from the equalizer with the equalizer 35 moved up near the cordstop I! when the blind is in the fully lowered position, .so that themanual raising of the blind would be by the fabric drop cord from theequalizer 35. Under certain conditions, it may be desirable to have thelift cords pass through loops, such as 50, secured to the ladder tapes,preferably near the slats, where the side members of the ladder tapeswill not move in or out appreciable during the folding operation whenthe blind is lifted. There clips may be firmly attached to the sidemembers of the ladder tape by passing through a hole in the edge of theladder tape, or they may be detachably fastened to the ladder tape asshown in my copending application Serial No. 1,720. With the offsetportion of the semi-stiff cross members of the ladder tape, it may befeasible to use slats with tongues in as shown in Figures 4 and 5 andwith cords at the opposite edges of the ladder tapes, or it may bepossible to use lift cords at the edge of the slats going between thestaggered ladder rungs, such as 901, and passing through a notch at theedge of the slat near the tongues 5a and 5b in order to avoid excessivefriction between the lift cords and the side members of the ladder tape.In this instance, the ladder tapes would not be removable but the offsetstiffened cross members would suitably mesh with the tongues of theslats and the clearance at the edge of the slats would provide freemovement of the lift cord next to the side members of the ladder tape.The side members of the ladder tape would, of course, have to fold atevery slat position which is feasible with very flexible side members inthe ladder tapes.

While I have shown some modifications of this invention, I do not wishto be limited to the structures as shown and the advantages of theinvention will be more clearly pointed out in the accompanying claim.

I claim as my invention:

In. a Venetian blind comprising a head rail, a tilt rail, a bottom rail,and ladder tapes including opposed side members and intervening slatsupporting cross rungs; the improvement comprising a pair of flexiblelifting elements disposed adjacent each ladder tape, said flexiblelifting elements being disposed outwardly of the planes of the oppositeedges of said side members, one of said flexible lifting elements beingdisposed contiguous to an edge of one side member and substantially inthe plane thereof, the other flexible element being disposed contiguousto the opposite edge of the other side member and substantially in theplane thereof, loop members secured to said edges of said side membersin vertical positions adjacent predetermined ones of said cross rungsand through which said flexible elements extend.

BROOKS WALKER.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,200,349 Walker May 14, 1940 2,285,033 Judels et a1 June 2,1942 2,301,485 Walker Nov. 10, 1942 2,311,716 Walker Feb. 23, 19432,317,660 Williams Apr. '27, 1943 2,535,926 Hunter Dec. 26, 1950

